I fixed it, but I have follow questions

[cptnbananajam]

I rewrote the line like this, and it captures and triggers. It also repeats the trigger whenever walked on. Is there a quick way to turn off the trigger if the trap should only trigger once?

I have the details setup this way, with half damage on save. However it doesn't give me half the damage as a result, nor does it apply damage to the token. Is there a way to fix the half damage? Is here a way to have it automatically assign damage to a token?

[tposney]

The damage roll is correct, it rolls the normal damage and if you are using midi-qol it applies half damage on save.

Are you using midi's auto apply damage? If not you need to do so - if you don't want it to actually apply damage set the auto apply damage to no + damage card. The GM only damage card has all the info/buttons to apply the damage to those who do not save.